Defense and prosecution lawyers in a military courtroom Monday battled over whether the most serious charge against Army Pfc. Bradley Manning – aiding the enemy – should be dropped along with several lesser charges, because the government failed to provide sufficient proof.

Aiding the enemy is a crime that can result in the death penalty, but prosecutors have said they will seek life in prison if Private Manning is found guilty.

The 21 contested charges against Manning stem from his giving the WikiLeaks website 700,000 classified files, combat videos, and diplomatic cables while he was serving as a junior intelligence analyst in Iraq in 2009 and 2010. Manning pleaded guilty in February to reduced versions of some additional charges.

At Monday’s court session at Fort Meade in Maryland, defense and prosecution lawyers began oral arguments on defense motions to acquit the 25-year-old soldier on the aiding-the-enemy charge and six lesser charges, the Associated Press reported.

To prove the aiding-the-enemy charge, prosecutors have to show that Manning knew the information he sent to WikiLeaks would be seen by Al Qaeda forces.

The defense seeks to portray Manning as an idealist, troubled by some of what he saw while in Iraq, and desiring to provoke public discussion. For example, CNN noted that the defense showed a video of a 2007 US Apache helicopter attack that killed 11 people in Baghdad, including a Reuters news photographer and his driver. Manning has said the video troubled him so much that he uploaded the images to WikiLeaks. He has acknowledged leaking documents but says his motive was to expose wrongdoing.

The defense team, which rested its case last week, also argues that some of the information Manning leaked was already publicly available. In its new motion, the defense contends that the prosecution has not presented incriminating evidence on the seven charges, and therefore Manning should be acquitted.

Meanwhile, prosecutors say Manning used military computers to download classified documents and caused them to be published on the Internet where they could be viewed by those seeking to kill US military personnel. Prosecutors say the information Manning leaked fell into the hands of Al Qaeda and its former leader, Osama bin Laden, and thus harmed national security.

During the trial, prosecutors offered evidence that Al Qaeda leaders reveled in the publication of the documents Manning stole and urged members to study the information before seeking ways to attack the US, the AP reported.

The result of the Manning trial could have some impact on a potential prosecution of former National Security Agency contractor Edward Snowden, who leaked information about the NSA's intelligence-gathering activities within the US. Like Manning, Mr. Snowden has said he was troubled by what he saw and sought to expose it for the good of the country.

"Anybody looking at this [Manning] case is going to have to say, 'We have to throw the book at this guy, or where does it end?' " Eugene Fidell, a former military lawyer who now teaches at Yale Law School, told Reuters

Manning has opted for a trial before a judge instead of a jury-based court-martial. At Monday’s court session, Col. Denise Lind, the judge in the case, said she would rule Thursday on the defense’s aiding-the-enemy motion.